Tap-holder.



No. 857,632. PATENTBD JUNE 25, 1907.

D; KIHLGREN.l

TAP HOLDER. APPLICATION FILED SEPT. l, 1906.

2 sHEBTs-sHBET 1.

,I 1 1 11,1111 1 lll/11111111114 4 www Y No.4 857,632. -PATENTED JUNE25, 19'07.

D. KIHLGREN.

TAP HOLDER.

APPLIUATLON PI En SEPTA 19 e.

If 0 ssHEBTs-SHBET 2.

MLM

DAVID KIHLGREN, OF SPRINGFIELD, MASSACHUSETTS.

TAP-HOLDER.

no. estese.

Specification of Letters Patent.

Patented June 25, 1907.

Application ledBeptember l, 1906- Selal NO- 332.991.

To rar/ZZ whom it may concern.-

Be it known that I, DAvrD KIHLGREN, a citizen oi' the United States ofAmerica, residing at Springfield, in the county of Hampden and State ofMassachusetts, have invented new and useful Improvements inTap- Holders,of which the following is a speciiication.

This invention relates to improvements in tool holders and moreparticularly to tap holders, and it has for its object to provide adevice that will prevent breaking or injuring the tap when an unduepressure or torsional strain is exerted thereon by the workman. It iswell known in the use of this class of tools that great care is requiredto be exercised in order not to exert too much torsional strain on thetap so as to prevent breakage; and this is especially true when taps ofthe smaller dimensions are used; a further object is' to provide anindicating device that will show to the workman the exact torsionalstrain that can be safely placed upon a tap of a certain size.

Broadly stated, the invention consists in providing the tap holder with,a bored out portion or receptacle for containing a series of disks;said disks being so arranged that when the tool is in use all-of thedisks will be carried around with the wrench and when undue torsionalstrain is placed upon the tap every alternate oneof the disks,which'carry the chuck piece, will remain stationary with lthe tap, andthe remaining disks, which are locked to the wrench, will slip on thesame.

l I also provide suitable means for varying the pressure on the disks. lIn the drawings which form a part of this application, with thereference characters marked thereon for indicating the elements of thedevice: Figure 1 is a top plan view of the wrench. Fig. 2 is a sideelevation of the same. Fig. 3 is a vertical, longitudinal seetional viewon the line 3-3 of Fig. 1. Fig. 4 is a top plan view ofa modification ofmy invention. Fig. 5' is a vertical longitudinal sectional view of thesame on line 5 5 of Fig. 4. Fig. 6 is a detailed view of one of thedisks that is held against rotation in the wrench. Fig. 7 is a ldetailedviewof a disk that is adapted to :be rotated when the wrench is in useand having a rectangular opening therethrough-for receiving the chuck.Fig. 8 is a side elevation of another modification of my invention andshowing the saine as applied to a spindle adapted for use in a drillpress or speed lathe. Fig. 9 is a longitudinal sectional view on theline 9-9 of Fig. 8. Fig. 10 is an end elevation of Fig. 8 and show ingthe means for locking the chuck piece in place in the spindle. Fig. 11is a detailed view of the chuck piece used in the form shown in Figs. 1,2 and 3. Fig. 12 is a detailed view of chuck piece used in the formshown in Figs. 4 and 5.

The detailed views shown in Figs. 6 and 7 represent elements that areadapted for use in all of the forms. Y c f Referring to the drawings indetail, a designates the handle portion of an ordinary tap tion of thetap wrench and is circular in form as shown in plan view in Fig. 1. Thisboss is bored out so as to provide a circular receptacle as shown indotted lines at c. This enlarged portion or boss also extends above theupper portion of the handle as shown at d. This part is threaded forreceiving an internally threaded tension cap c. The bored out portion chas recesses out at diametrically opposite points and opening into thesame as hown at f. These recesses are for the purpose of receiving theprojecting ends g of the disk h as shown in Fig. 7. Placed immediatelyin contact with the disk h is a circular disk i, having the rectangularopening therethrough. The disks h and i arearranged one above the otheras shown in Fig. 3, that is alternating with each other until the samelie iiush, or nearly so, with the top of the portion d. k designates anelastic inverted tension disk that is placed on top of the uppermostdisk as shown in Fig. 3 with its outer edge engaging the innerhorizontal surface of' the cap e as shown at m. 'n 'designates a chuckpiece or tool holder for receiving the tap. This chuck piece is maderectangular or square in shape for ,a greater portion of its length andof a dimension equal to the opening j in the disk 'L so as to closelyfit the same. It should be stated that the opening o in the disk h islarge enough t0 freely allow the chuck fn.' to pass therethrough. Afterthe disks 71, and f are assembled as shown in Fig. 3 the chuck piece nis passed through an opening p in the lower side of the wrench k andthrough the series of assembled disks; the

- upper cylindrical end as shown at q is passed through the opening r inthe cap piece e and a knurled nut s screwed onto the threaded portion tfor holding the chuck n in place.

It will be observed that the tension cap e wrench, b designates the bossor enlarged porp IOO is provided on its periphery with a series ofindentations or notches fu.. These notches are forlthepurposeofireceiving the beaded end uQof the pointer o for locking thetension cap e at any desired point at which it is 4 safe to use the tapof a certain size, this point having previously been determined bytrial. -It will be observed that upon the rotation of the tension cap ethe same is threaded on to the portion t, drawing down or placing undertension the elastic disk f. This disk in turn places under pressure theseries of disks h and t with a consequent result thatthe frictional orslipping resistance between the disks is increased, and lessened whenthe tap is turned in a reverse direction.

In operation., all of the disks drive or rotate with the wrench turningthe tap, as un: derstood, by reason of the friction that eX- istsbetween the disks. The disks being carried around by the workman,rotating the handles a. By increasing the number of disks it Will beunderstood that the frictional resistance is correspondingly increased,and therefore less rotation of the tension cap e is re uired.

eferring to the modification shown in Fig. 5, substantially the sameconstruction is employed as that shown in Figs. l, 2 and 3. In this form:l: designates a spring plate secured to the handle by the screw y atone end and the opposite end of the plate is drawn down by the screw z.This spring plate engages the uppermost disk of the series and transmitspressure to all of the disks below with a result that the frictionbetween the movable and immovable Washers is increased.

Referring to the modification shown in Fig. 8,A in which my invention isapplied to a spindle which is designated at 2. The same is provided withan enlarged portion 3 that is bored out and recessed in the same manneras described above in connection with Figs. l, 2 and 3. This part 3 isthreaded at its outerl end as shown at 4 to receive a tension cap 5 inthe same manner as described above, and an elastic `vcup-shaped disk 6.The tension cap 5 is notched on its outer edge for receivin a pointer 7,for holding the ca 5 in any esired place, it being understoo thatrotation of the cap 5 places the requisite amount of pressure betweenthe several disks. The chuck piece 8 used in this form is held in placeby means of a latch 9 pivoted to the cap 5 at the point 10. The circularportion engaging the annular groove 12 in the chuck iece 8. The latch 9beingretained in its ockin position under the head of the screw 13. npractice I use some powdered substance, as graphite, between the disksto prevent the sticking together of the metal surfaces.

The llchuck piece n as shown in Fig. 12 is adapted for use in the formshown in Fig. 5;

The circular ends 'n.2 having a bearing in the plate a: and in the lowerside of the wrench. The shoulders rn.3 engage the under side ofthe platea; and the bottom of the bored out portion.

It will be seen that in all theforms I have provided a device that willprevent undue strain being placedupon the tap, and that the pressurethat is safe for any given size tap can be setv in advance as shown bythe index numerals on the tension cap e as shown at 14. i

In using the above described tap, should undue/ torsional. pressure beplaced on the wrench, the tap will remain stationary, and a slipping orrotative movement will occur between the disks 7L and i, as understood,thlllpreventing the tap being broken.

at I claim, is

1. ,In a ta -holder having a bored out portion, two series of disksmounted therein, one series being held against rotation, a chuckpiececarried by one of the series of disks, means for varying the pressure onthe series whereby one series of disks will slip on the other serieswhen undue torsional strain is eX- erted on the holder.

2. In a tap-holder having a bored out portion, recesses communicatingwith said bored out portion, a series of disks provided with projectingends mounted in the bored outl portion and their projecting endsengaging said recesses, another series of disks mounted in the bored outportion and alternately arranged between the iirst mentioned disks, saidsecond series of disks havin a rectangul'ar opening therethrough, the stseries of disks having a circular opening therethrough, a chuckrectangular in sha e engaging the rectangular opening in saidisk'whereby, when the holder is rotated the first series of disks willtransmit rotative movement to said chuck-piece and whereby when undueApressure is placed on the holder, rotative movement of the chuck-piecewill cease.

3. In a tap holder, means for rotating a tap, said means consisting oftwo series of frictional disks carried by the holder, means forpreventing the rotation of one series, and means for varying thepressure between the disks as described.

4. In a tap holder provided with means for holdin a tap, said meansbeing driven by a multip e series of disks alternately arranged, andmeans for varying the pressure between said disks for limiting theamount of torsional strain that can be exerted upon the tap.

5.- In a holder of the class described, a series of rictional diskscarried thereby, one series provided with locking means for engaging theholder proper, the other series being alternately arranged between saidfirst mentioned series, elastic means vfor varying the pressure betweenthe two series of disks IOO IIO

and means for holding, a tap, said means oonsisting of a chuck piececarried by the second serios of disks.

(i. In a tap holder provided with means for holding a tap, said meansbeing driven by a multiple series of disks alternately arranged, andmeans for Varying the pressure between said disks for limiting theamount of torsional strain that can be exerted u on the tap', the seriesof disks bein in p anes at ro right angles to the axis of t etap-holding means.

DAVID KIHLGREN. Witnesses:

HENRY A. CHAPIN,

H. W. BOWEN.

